The present invention relates generally to articles having decorative coatings or finishes provided thereon and methods of producing such articles. More specifically, the present invention relates to articles and methods for producing articles which have multi-tone coatings provided thereon.
Colored coatings have been provided on articles using physical vapor deposition (PVD) or chemical vapor deposition (CVD) methods. PVD coatings are at present available in a range of colors on such commercial products as plumbing products, home hardware such as doorknobs and hinges, automotive products, recreational products, and various other products.
PVD and CVD decorative coatings in general offer many performance advantages such as high hardness, abrasion resistance, corrosion resistance, chemical resistance, etc. as compared to conventional polymer and electroplated coatings. Although PVD and CVD coatings are available in a variety of colors, presently available PVD and CVD coatings generally have a uniform color over the entire substrate surface. It may be desirable, however, for certain applications to use a PVD or CVD coating having a visibly-patterned, multi-color appearance (e.g., for creating products having, for example, streaked, speckled, marbled, “antique”, “aged”, or “distressed” finishes, or having decorative or informational digitized images incorporated into the surface finish).
Conventional methods for creating patterned decorative finishes on products such as those mentioned above generally utilize polymer coatings for either coloration or protection. It is known to use paints, lacquers, etc. to create patterned finishes directly on a substrate surface. It is also known to thermally, chemically, and/or mechanically treat substrate surfaces to produce patterned finishes, but such treated surfaces are often not durable and require a polymer topcoat for protection against abrasion and corrosion. Polymer coatings may be susceptible to abrasion, solvents, and household chemicals, and may develop pinholes through which corrosion of the substrate can initiate.
PVD coatings, in contrast, are generally very hard and resistant to abrasion and chemical attack, and are superior to polymer-based coatings for many applications. While patterned PVD and CVD coatings have been used in the electronics industry for purposes of fabricating printed and integrated circuits, such coatings have not conventionally been used to provide decorative coatings (e.g., visibly-patterned, multi-colored decorative coatings). Such patterned PVD and CVD coatings are generally made of materials selected for their electronic (as opposed to decorative) properties and are used to produce non-decorative patterns that are too small to be visible to the human eye without magnification. In addition, such patterning processes often handle only flat substrates and a single substrate at a time, which would be unsuitable for the mass-production of consumer products.
It would be advantageous to provide a decorative coating or finish for an article that is provided using PVD and/or CVD methods that has a patterned appearance, which will not rub or scrub off in normal use, which is scratch and corrosion resistant, can withstand common household chemicals and solvents, and does not age or degrade in sunlight or under exposure to outdoor conditions. It would also be advantageous to provide articles having decorative coatings which provide an aesthetically-pleasing appearance that is visible to the unaided human eye and that are produced using methods which are suitable for mass-production. It would be desirable to provide coatings, articles, and methods which exhibit any one or more of these or other advantageous features as may be understood by those of ordinary skill in the art reviewing this document.